Question

如图,点D,E分别在三角形ABC的边AB,AC上,BE与CD交于点O,角AEO+角ADO=180度.

Answer 1

①∵∠BCF=∠ACD,∴∠OCG=∠ACF,

∵AF⊥AB,OG⊥BC,∴∠A=∠GOC,

∵∠ADO+∠AEO=180°,∴∠A+∠DOE=180°,

又∠DOE+∠EOC=180°,

∴∠A=∠EOC,

∴∠GOC=∠EOC.